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71.
膝屈曲状态胫股关节压应力光弹性分析 总被引:2,自引:0,他引:2
以胫股关节光弹材料模型模拟膝关节在屈曲0°、10°、20°和30°状态下加载。结果显示胫股间接触面积内髁大于外髁,应力分布外髁大于内髁,最大应力分布于接触部位中心点附近。随着膝关节屈曲角度增加,(1)中心点后移,30°以内胫股间打滑率内侧为40.23%,外侧为45.92%;(2)胫骨平台两中心点内移,中心点间距增加;(3)胫股间接触面积减少;(4)应力峰值增加,其增加率远大于面积减少率。实验结果提示膝关节畸形矫正时,要注意恢复胫股间的正常对合与应力分布。 相似文献
72.
五种免疫相关性心血管疾病的免疫学研究 总被引:4,自引:0,他引:4
对扩张型心肌病、风湿性心脏病,原发性高血压,冠心病及肥厚型心肌病进行外周血清可溶性白细胞介素2受体,T淋巴细胞亚群及自然杀伤细胞活性的检测,并与健康对照组比较,结果显示:DCM组,RHD组及EHT组的sIL-2R明显高于NC组,而DCM、RHD风湿活动组的NK活性低于NC组,EHT组NK活性高于NC组。 相似文献
73.
David P. Bazett-Jones Ren Li Eden Fussner Rosa Nisman Hesam Dehghani 《Chromosome research》2008,16(3):397-412
Electron microscopy has been the ‘gold standard’ of spatial resolution for studying the structure of the cell nucleus. Electron
spectroscopic imaging (ESI) offers advantages over conventional transmission electron microscopy by eliminating the need for
heavy-atom contrast agents. ESI also provides mass-dependent and element-specific information at high resolution, permitting
the distinguishing of structures that are primarily composed of protein, DNA, or RNA. The technique can be applied to understand
the structural consequences of epigenetic modifications, such as modified histones, on chromatin fiber morphology. ESI can
also be applied to elucidate the multifunctional behavior of subnuclear ‘organelles’ such as the nucleolus and promyelocytic
leukemia nuclear bodies.
The authors dedicate this paper to the memory of Ying Ren (1961–2007). We all benefited from knowing her. Our research advanced
through the technical creativity she provided. 相似文献
74.
James D. Weinrich Ph.D. Peter J. Snyder Ph.D. Richard C. Pillard M.D. Igor Grant M.D. Denise L. Jacobson M.P.H. S. Renée Robinson R.N. M.A. M.F.C.C. J. Allen McCutchan M.D. 《Archives of sexual behavior》1993,22(2):157-168
Many researchers interested in sexual orientation can be separated into two camps: The lumpers, who try to reduce sexual classifications to as small a number of categories as possible, and the splitters, who try to show differences among groups and individuals that make classification schemes increasingly difficult and/or intricate. We report factor analyses of the Klein Grid (a questionnaire with 21 sexual orientation items) to see how many factors emerge in two samples of strikingly different origins. In both samples, the first factor to emerge loaded substantially on all of the Klein Grid's 21 items. This factor accounted for a majority of the variance. In both samples, a second, correlated factor emerged which indexed a separation between most of the items and those having to do with social and/or emotional preferences. In both samples, a third correlated factor also emerged, but this factor differed between the two populations: one refined the social/emotional distinction and the other distinguished ideal behavior from past and current behavior. We conclude on the basis of our analysis that both the lumpers and the splitters are correct.Supported by NIMH grants IP50 MH 45294 and R01 MH 43298. 相似文献
75.
K A Watanabe K Harada J Zeidler J Matulic-Adamic K Takahashi W Y Ren L C Cheng J J Fox T C Chou Q Y Zhu 《Journal of medicinal chemistry》1990,33(8):2145-2150
1-(3-Azido-2,3-dideoxy-2-fluoro-beta-D-arabinofuranosyl)thymine (6, F-AZT) and 1-(2,3-dideoxy-2-fluoro-beta-D-threopentofuranosyl)cytosine (12, F-DDC) were synthesized from the potent antiherpes virus nucleosides 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)thymine (1, FMAU) and 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine (FIAC) in the hope that introduction of a 2-"up"-fluoro substituent might potentiate the anti-HIV activity of AZT and DDC. FMAU (1) was converted in three steps into 2,3'-anhydro-1-(2-fluoro-2-deoxy-5-O-trityl-beta-D-lyxofuranosyl)thymine (4), which when treated with NaN3 followed by detritylation afforded 6. F-DDC was prepared by two methods. Tritylation of FIAC followed by treatment of the product with thiocarbonyldimidazole afforded the 5'-O-trityl-3'-O-(imidazolyl)thiocarbonyl nucleoside 9. Upon radical reduction of 9 with Bu3SnH and AIBN, 5'-O-trityl-DDC 10 was obtained. Compound 10 was detritylated to give 12, which (when obtained by this procedure) resisted crystallization, but the diacetate 12' was obtained in crystalline form. Alternatively, FAC (14) was converted into N4,O5'-dibenzoyl derivative 15, which was treated with thiocarbonyldiimidazole. Reduction of 16 with Bu3SnH/AIBN followed by debenzoylation afforded 12, which was obtained in crystalline form. F-AZT did not exhibit any significant activity against the human immunodeficiency virus (HIV) in vitro. F-DDC, however, showed activity against HIV-1, but the therapeutic index is much inferior to that of AZT. 相似文献
76.
Ren ZY Tucker R Landas S Lubaroff DM Sparrow HK Loening SA 《The Journal of lithotripsy & stone disease》1990,2(3):211-219
Male Copenhagen rats implanted with Dunning R3327 prostate carcinoma were treated with regional hyperthermia and high energy shock waves (HESW). Twenty-four rats were divided into four equal groups. All rats in one group were matched with the corresponding rats in the other three groups according to tumor size. Hyperthermia was created by the resistive heating of a 22-gauge 1.5-cm needle; HESW were generated by the Dornier XL-1 experimental lithotripter. In two hyperthermia treatments administered 48 hours apart, the tumor was heated to 46.5 degrees C for 2 hours; HESW treatment involved 1,600 shocks at 18 kV. Twenty-nine days after initiation of this study, animals were sacrificed and tumor growth calculated. Tumor growth in group 1 (combined hyperthermia and HESW) was significantly delayed between the 7th and 29th day (p = 0.05). In group 2 (HESW alone), tumor growth was significantly delayed between the 7th and 22nd day (p = 0.01), while tumor growth in group 3 (hyperthermia alone) was delayed between the 3rd and 22nd day (p = 0.02). On day 22, mean percent change in tumor growth in the control group exceeded that of group 1 by 449% (p = 0.015) as well as that of groups 2 and 3, by 350% (p = 0.034) and by 268% (p = 0.049), respectively. As previous reports demonstrate the efficacy of hyperthermia in combination with irradiation or chemotherapy for the treatment of prostate carcinoma, our results indicate hyperthermia in combination with HESW may also be a useful treatment modality. 相似文献
77.
作者研究了侧金盏花中强心甙的反相高效液相色谱测定方法,并对吉林产的侧金盏花中强心甙的相对含量进行了测定。测定结果表明,吉林产的侧金盏花中主要含甙元A、甙元B、加拿大麻甙、铃兰毒甙和毒毛旋花子甙元等强心成分。 相似文献
78.
79.
目的 观察哇巴因与地高辛对大鼠肝脏钠泵基因表达的影响 .方法 分别给大鼠注射哇巴因 (2 0 μg· kg- 1·d- 1 )、地高辛 (32 μg·kg- 1·d- 1 )和生理盐水 (1m L· kg- 1·d- 1 ) ,观察给药后 6wk大鼠血压的动态变化 ;并分别应用分子生物学 RT- PCR及免疫组织化学技术 ,探讨各组大鼠肝脏钠泵 α1 ,α2 及 α3 亚单位 m RNA及蛋白水平基因表达的改变 .结果 给予哇巴因 2 wk后大鼠血压开始升高 ,至 6 wk时明显高于生理盐水组 (17.7± 1.2 ) vs(15 .4± 1.1) k Pa,P<0 .0 1) ,而实验过程中地高辛组血压与对照组比较差异不明显 .无论是在 m RNA水平还是在蛋白水平 ,哇巴因对大鼠肝脏钠泵α1 亚单位表达无影响 ,而地高辛使α1 亚单位表达增强 ;两组大鼠 α2 亚单位表达均无改变 ;哇巴因使 α3 亚单位蛋白水平表达减弱 ,而 m RNA水平增强 ,地高辛组大鼠肝脏钠泵 α3 亚单位无论在 m RNA水平及蛋白水平表达均增强 .结论 哇巴因在高血压发病中可能起着重要作用 ;哇巴因与地高辛可导致不同的钠泵基因表达改变 ,为进一步揭示内源性哇巴因生理与病理作用以及洋地黄类药物药理与毒理作用的分子机制提供了理论及实验依据 相似文献
80.
通过对小鼠补体受体Ⅱ型基因(CR2)进行定点突变,然后将野生型和突变型小鼠CR2/1(MCR2/1)及人CR2(hCR2)用电穿孔方法导入小鼠SP2/0进行表达,采用免疫组织化学等方法鉴定阳性细胞系。用EB病毒对转染阳性细胞进行感染,EBER-1杂交结果显示,仅转染hCR2和突变型MCR2(mtMCR2)的SP2/0细胞感染了EB病毒,前者感染EB病毒的阳性率较后者高很多。这为进一步研究EB病毒进入细胞的机制及建立EB病毒相关的鼻咽癌动物模型奠定了良好的基础。 相似文献